/* inih -- simple .INI file parser

inih is released under the New BSD license (see LICENSE.txt). Go to the project
home page for more info:

http://code.google.com/p/inih/

*/

#include <stdio.h>
#include <ctype.h>
#include <string.h>

#include "ini.h"

#define MAX_LINE 200
#define MAX_SECTION 50
#define MAX_NAME 50

/* Strip whitespace chars off end of given string, in place. Return s. */
static char* rstrip(char* s)
{
    char* p = s + strlen(s);
    while (p > s && isspace(*--p))
        *p = '\0';
    return s;
}

/* Return pointer to first non-whitespace char in given string. */
static char* lskip(const char* s)
{
    while (*s && isspace(*s))
        s++;
    return (char*)s;
}

/* Return pointer to first char c or ';' comment in given string, or pointer to
   null at end of string if neither found. ';' must be prefixed by a whitespace
   character to register as a comment. */
static char* find_char_or_comment(const char* s, char c)
{
    int was_whitespace = 0;
    while (*s && *s != c && !(was_whitespace && *s == ';'))
    {
        was_whitespace = isspace(*s);
        s++;
    }
    return (char*)s;
}

/* Version of strncpy that ensures dest (size bytes) is null-terminated. */
static char* strncpy0(char* dest, const char* src, size_t size)
{
    strncpy(dest, src, size);
    dest[size - 1] = '\0';
    return dest;
}

/* See documentation in header file. */
int ini_parse(const char* filename,
              int (*handler)(void*, const char*, const char*, const char*),
              void* user)
{
    /* Uses a fair bit of stack (use heap instead if you need to) */
    char line[MAX_LINE];
    char section[MAX_SECTION] = "";
    char prev_name[MAX_NAME] = "";

    FILE* file;
    char* start;
    char* end;
    char* name;
    char* value;
    int lineno = 0;
    int error = 0;

    file = fopen(filename, "r");
    if (!file)
        return -1;

    /* Scan through file line by line */
    while (fgets(line, sizeof(line), file) != NULL)
    {
        lineno++;
        start = lskip(rstrip(line));

#if INI_ALLOW_MULTILINE
        if (*prev_name && *start && start > line)
        {
            /* Non-black line with leading whitespace, treat as continuation
               of previous name's value (as per Python ConfigParser). */
            if (!handler(user, section, prev_name, start) && !error)
                error = lineno;
        }
        else
#endif
            if (*start == ';' || *start == '#')
            {
                /* Per Python ConfigParser, allow '#' comments at start of line */
            }
            else if (*start == '[')
            {
                /* A "[section]" line */
                end = find_char_or_comment(start + 1, ']');
                if (*end == ']')
                {
                    *end = '\0';
                    strncpy0(section, start + 1, sizeof(section));
                    *prev_name = '\0';
                }
                else if (!error)
                {
                    /* No ']' found on section line */
                    error = lineno;
                }
            }
            else if (*start && *start != ';')
            {
                /* Not a comment, must be a name[=:]value pair */
                end = find_char_or_comment(start, '=');
                if (*end != '=')
                {
                    end = find_char_or_comment(start, ':');
                }
                if (*end == '=' || *end == ':')
                {
                    *end = '\0';
                    name = rstrip(start);
                    value = lskip(end + 1);
                    end = find_char_or_comment(value, '\0');
                    if (*end == ';')
                        *end = '\0';
                    rstrip(value);

                    /* Valid name[=:]value pair found, call handler */
                    strncpy0(prev_name, name, sizeof(prev_name));
                    if (!handler(user, section, name, value) && !error)
                        error = lineno;
                }
                else if (!error)
                {
                    /* No '=' or ':' found on name[=:]value line */
                    error = lineno;
                }
            }
    }

    fclose(file);

    return error;
}
